This grant application details a series of anticipated research undertakings by the principal investigator who continues to coordinate his research interests with the activities of other investigators with expertise in pathology, biochemistry, physiology, biophysics, radiology and cellular transport. With the combined and coordinated input of all investigators, we plan to achieve a more detailed and correlated understanding of the metabolism of calcium, phosphate and vitamin D and its metabolism in acidotic and uremic disorders, diabetes mellitus, and in diseases characterized by persistent hypophosphatemia. Isolation and purification of intestinal calcium binding protein(s) will proceed concurrently with other studies designed to evaluate the relationship between intestinal calcium and phosphate transport, vitamin D bioactivation, and bone turnover. Differential factors which initiate or retard dialysis bone disease in males and females will be evaluated and the relationship between acquired disturbances in bone mineralization and resorptive and carbohydrate metabolism explored.